Re: head work larger valves, 10:1 compression (archive)

Does anyone know how much it would cost to port and polish head/ put on larger valves or try and do the 10:1 coversion? If so has anyone done this to their car? Have any specs or prices, with the results i'd see?
josh
535i to M535is
colorado
thx for the help in advance

Josh,
My son Nathan and I just got finished building an uprated big 6 for our '86 535. I would leave the head work to the experts. This is the most important aspect of performance engine work and there are too many tricks out there that do make a difference. We used a Metric Mechanic Hi Flow head and we were very pleased with the quality of the work, impressive to say the least. I totaled up all the parts needed to duplicate the work, ie. perfomance cam, springs, rockers, valves etc.and the cost adds up quick.
We went to 10:1 compression, at the same time increasing bore size to 94mm, which equates to a 3.71 kick ass motor.If you rebore it does not cost much more to go up to 94mm.
Source forged pistons from PAECO. They are only around $400/set. I got rings from Total Seal at a cost of $130+/-, along with lightened wrist pins.
While in there replace all bearings, timing chain and sprockets, oil pump, pump chain and sprockets, seals etc.
You can just keep going from here, depnding on what you want to spend.
We went with a set of Bavarian Autosport headers mated to a B&B triFlow exhaust and are very happy with the combination in both sound and perfomance.
Plan on spending $3000+/-, plus headers to get a kick ass 3.71 big 6, that you won't regret.
Contact me if you need any further info.
Good Luck,

Tom and Nathan in PA

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